Experimental comparison of albumin-sealed and gelatin-sealed knitted Dacron conduits. Porosity control, handling, sealant resorption, and healing.

Two high-porosity knitted Dacron vascular grafts sealed with aldehyde cross-linked gelatin or albumin were compared with respect to the following characteristics. Porosity control by the absorbable sealant was assessed with a water porosity meter at 120 mm Hg pressure. Ease of suturing was determined by an objective needle penetration test. Sealant resorption was assessed histologically in a subcutaneous immature rat model as well as in circulatory implants. Gross and microscopic healing characteristics were compared in circulatory implants in the thoracic aorta of sheep with use of a composite conduit in every animal, which allowed direct comparison of the two graft materials and minimized differences in healing between individual animals. Both grafts demonstrated excellent porosity control and better handling characteristics than woven Dacron. Sealant resorption was generally rapid, although residual albumin sealant was often seen adjacent to anastomoses. Residual sealant appeared to result in focally poor healing with focal loss of adhesion of surrounding tissue to graft. We conclude that details of sealant preparation and application can importantly influence the performance of presealed knitted Dacron grafts and should be carefully evaluated in the laboratory before clinical implantation is begun.